What Does a Drug Cost? It Depends on Where You Live.

What you pay at the pharmacy for generic drugs can vary widely based on where you live, according to a new analysis by the consumer website GoodRx.

The study, which looked at 500 commonly used drugs in 30 American cities, highlights just how unpredictable drug prices can be. The cost of common drugs like the generic version of the cholesterol drug Zocor, or the diabetes drug metformin, differ significantly from coast to coast.

GoodRx looked at the average cash price of the drug at a pharmacy — something not every consumer will have to pay. Most people have insurance coverage for their prescriptions, and consumers can often take advantage of discount programs. But a growing number of people are being asked to pay for a greater share, sometimes with a deductible.

Some disparities obviously result from a higher cost of living — New York and San Francisco were the most expensive cities in the country for drugs. But prices can vary widely even between similar cities in the same state: Cleveland’s pharmacy prices were 2.5 percent above the national average, while not far away, Columbus had prices that were nearly 22 percent below average. In Cleveland, the generic version of Paxil, the antidepressant, costs about $46.94, while in Columbus, someone would pay $20.87.

Thomas Goetz, the chief of research at GoodRx, said many factors are likely playing a role, like the prevalence in some areas of big-box stores like WalMart and Costco, which sell generic drugs at cheap prices.

But that can’t entirely explain what’s going on. Much can still be chalked up to the “drug prices make no sense” theory, he said. Generic drug manufacturers often charge different prices for versions of the same drug, and pharmacies can then mark up the drug in a variety of ways.

“It’s one more indication of how nonsensical drug prices can be, and how important it is to be vigilant about what you are being asked to pay,” he said.

Leigh Purvis, director of health services research at the AARP’s public policy institute, said the price variation isn’t just city by city — even pharmacies on the same block can sell drugs at vastly different prices. Some states, like New York and Florida, offer their own comparison sites so consumers can shop around for drugs.

If consumers do shop around, she advised keeping in touch with a single doctor or pharmacist who knows all of the drugs that are prescribed. “You don’t want to have an adverse reaction or interaction because there is no one keeping an eye on the big picture,” she said.

Here is a list of five commonly used drugs, and what the average cash prices are at pharmacies in five major cities.